get_ep.m

一个UWB仿真程序包

%
% EP stands for error protection
%
% EP contains the ths, scrambling and interleaver_state
%
% function [ep,symbol_start] = get_ep(PACKET_LENGTH, ...
%                                     SYMBOL_LENGTH, ...
%                                     BURST_LENGTH, ...
%                                     samples)
%
function [ep] = get_ep(PACKET_LENGTH, ...
                       SYMBOL_LENGTH, ...
                       BURST_LENGTH, ...
                       samples)

NHOP = SYMBOL_LENGTH/BURST_LENGTH/4;
fprintf('Number of hops available = %d\n',NHOP);

% $$$ % Get the polarity of the bursts
% $$$ polarity = 2*round(rand(1,))-1;
% $$$ 
% $$$ % Time-hopping sequence
% $$$ ths = discr_unif(0,NHOP-1,PACKET_LENGTH);

% Get the polarity and the time-hopping sequence
init_reg = [1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0];
[polarity,ep.ths] = ...
    mex_scrambler(1,PACKET_LENGTH*BURST_LENGTH,BURST_LENGTH,log2(NHOP),init_reg);
ep.scrambling = 2*polarity-1;

% Get the interleaver state
%ep.interleaver_seed = round(2^20*rand);
ep.interleaver_seed = [];